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Toyota Matrix 07 ECM problem

2375 Views 1 Reply 2 Participants Last post by  John Anthony
Ok a quick backstory to this problem. Last summer I was randomly driving when the check engine light turned on and my toyota matrix lost acceleration and went into LIMP mode. It said it had a ECM problem on the check engine light. Well I just turned off the car, started it back up and didn't have any problems for a bit. Well fast forward a few months this problem started happening every couple days. You would be driving and the car would go into LIMP mode. It would be that ECM error code on the check engine light.. So I assume that the ECM is going out. Being the cheap skate I am I went on ebay and bought a part. I pay the dealer to get it installed which was quite annoying because in the middle of the job they randomly told me it's going to cost 80$ more than previously thought because something about having to reprogram my anti theft on my key. Anyway back to the point. I have them reprogram the ECM and off I go. A few days later the exact problem comes back. I talk to a mechanic that is not with the dealer and he said many ECM for the toyota matrix you can buy online, several of them were faulty between the certain years that I bought it for. So I pay him to install a new ECM that supposedly doesn't have these errors.. Well guess what, the exact same problem comes back and I don't want to keep throwing money into this thing. On top of that randomly two new codes popped up that said the crankshaft and camshaft position sensor went out, two seperate codes. I'm having a really hard time believing they both went out at the same time and I'm wondering if it has something to do with the ECM problem. Anyway at this point I have no idea what to do. I was researching online and someone had said that a faulty 3rd party brake light was causing their ECM to short out. But that knowledge doesn't help much because that means an endless list of things could be shorting it out. If it helps any, right before the ECM code gets triggered the dashboard lights flicker. Anyway, sorry this is so long, I am just wondering if anyone has any ideas before I try to sell this car for cheap..

the codes it throws is P0606 for the ECM, P0340 for the camshaft, and P0335 for the crankshaft.
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Something is shorting making that code come up. It's obviously NOT the ECM. Check out these two links and do some more research. Of particular interest is post #3 of this first link below. It's about a Chevy, but you may be interested since it's a similar situation. Here's a quote from post #3:

I ran into a Chevrolet a couple weeks ago with similar symptoms (intermittent loss of acceleration, check engine light) and it ended up being a 5v reference wire shorting to the camshaft position sensor's signal wire. It's entire harness was melted causing intermittent shorting. This was killing one of the 5v reference circuits in the computer. It was setting the P0606 code, as well as another code for loss of 5v reference "B", and a few other codes as well. It ended up not needing a computer.

The whole thread is here:

Here's another thread that gives another idea:

Good luck and let us know what you find out.
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